Wander Jager

University of Groningen | RUG · Groningen Center of Social Complexity Studies

Models of socio-environmental or social-ecological systems (SES) commonly address problems requiring interdisciplinary scientific expertise and input from a heterogeneous group of stakeholders. In SES modelling multiple interactions occur on different scales among various phenomena. These scale phenomena include the technical, such as system variab...

Twelve years ago, the European Union began with the gradual phase-out of energy-inefficient incandescent light bulbs under the Ecodesign Directive. In this work, we implement an agent-based simulation to model the consumer behaviour in the EU lighting market with the goal to explain consumer behaviour and explore alternative policies. Agents are ba...

This paper introduces the methodology of Agent Based Modelling (ABM), explains how it contributes to understanding the dynamics of climate relevant behaviour, and discusses the challenges to implementing behavioural theory in ABMs. Next an overview will be given on recent advances in environmentally relevant ABMs. The conclusions address the future...

Incorporating representations of human decision-making that are based on social science theories into social-ecological models is considered increasingly important – yet choosing and formalising a theory for a particular modelling context remains challenging. Here, we reflect on our experiences of selecting, formalising and documenting psychologica...

Most urban planning projects are implicitly based on the premise that people will adapt their behaviour to a new situation, be that the development of a new railroad, dedicated cycle lanes or the revitalisation of a neighbourhood. Sometimes, such behavioural changes are very smooth and quick, but usually many people are unsure about the implication...

International migration implies the coexistence of different ethnic and cultural groups in the receiving country. The refugee crisis of 2015 has resulted in critical levels of opinion polarization on the question of whether to welcome migrants, causing clashes in receiving countries. This scenario emphasizes the need to better understand the dynami...

International migration implies the coexistence of different ethnic and cultural groups in the receiving country. The refugee crisis of 2015 has resulted in critical levels of opinion polarization on the question of whether welcome migrants, causing clashes in the receiving countries. This scenario emphasizes the need to better understand the dynam...

International migration implies the coexistence of different ethnic and cultural groups in the receiving country. The refugee crisis of 2015 has resulted in critical levels of opinion polarization on the question of whether to welcome migrants, causing clashes in receiving countries. This scenario emphasizes the need to better understand the dynami...

In this paper we explore how social influence may cause a non-linear transition from a clean to a littered environment, and what strategies are effective in keeping a street clean. To study this,we first implement the Goal Framing Theory of Lindenberg and Steg (2007) in an agent based model. Next, using empirical data from a field study we paramete...

The transition from fuel cars to electric cars is a large-scale process involving many interactions between consumers and other stakeholders over decades. To explore how policies may interact with consumer behavior over such a long time period, we developed an agent-based social simulation model. In this model, detailed data of 1795 respondents hav...

Agent-based modelling (ABM) proves successful as a methodology for the social sciences. To continue bridging the micro-macro link in social simulations and applying ABM in real-world conditions, conventional and often simplified models of decision-making have to be utilized and extended into psychologically plausible models. We demonstrate the cont...

Formal models are commonly used in natural resource management (NRM) to study human-environment interactions and inform policy making. In the majority of applications, human behaviour is represented by the rational actor model despite growing empirical evidence of its shortcomings in NRM contexts. While the importance of accounting for the complexi...

Using psychological theory in agent formalisations is relevant to capture behavioural phenomena in simulation models (Enhance Realism Of Simulation - EROS). Whereas the potential contribution of psychological theory is important, also a number of challenges and problems in doing so are discussed. Next examples of implementations of psychological th...

This book highlights recent developments in the field, presented at the Social Simulation 2015 conference in Groningen, The Netherlands. It covers advances both in applications and methods of social simulation. Societal issues addressed range across complexities in economic systems, opinion dynamics and civil violence, changing mobility patterns, d...

We propose a hybrid microsimulation and agent-based model of mobility integrating migration and residential mobility. We tested it on the evolution of the population of the Cantal, a French “département” with 150,000 inhabitants. We calibrated it using various data sources from 1990 to 2006, and tested its predictions on other data of the same peri...

This paper studies a model of agents having an opinion about each other agent and about themselves. During dyadic meetings, the agents change their opinion about themselves and about their interlocutor in the direction of a noisy perception of the opinions of their interlocutor. Moreover highly valued agents are more influential. This model produce...

Theoretical and experimental studies from psychological and behavioral sciences show that heuristics and social networks play an important role in decision-making under risk. The goal of this paper is to investigate the effects of empirical social networks and different behavioral rules on farmers’ irrigation adoption under drought risk and its imp...

Climate change, biodiversity loss, antibiotic resistance, and other global challenges pose major collective action problems: A group benefits from a certain action, but no individual has sufficient incentive to act alone. Formal institutions, e.g., laws and treaties, have helped address issues like ozone depletion, lead pollution, and acid rain. Ho...

In this chapter, we discuss the implications of complexities in societal systems for management. After discussing some essential features of complex systems, we discuss the current focus of managers and management theory on prediction and the problems arising from this perspective. A short overview is given of the leadership and management literatu...

In this chapter, we discuss the consequences of complexity in the real world together with some meaningful ways of understanding and managing such situations. The implications of such complexity are that many social systems are unpredictable by nature, especially when in the presence of structural change (transitions). We shortly discuss the proble...

This paper presents an extension to an agent-based model of opinion dynamics built on dialogical logic DIAL. The extended model tackles a pervasive problem in argumentation logics: the difference between linguistic and logical inconsistency. Using fuzzy logic, the linear ordering of opinions, used in DIAL, is replaced by a set of partial orderings...

In this paper we apply the updated consumat approach to the case of diffusion of electric cars. We will discuss how data from a large sample can be used to parameterize a number of main behavioural drivers, and how these relate to behavioural processes. At this stage we explain how the data fit in the framework, and whereas a model is currently und...

This article provides an overview of the social simulation approach to the study of social phenomena. We focus especially on the relevance of heterogeneity of social behavior and dynamics and the complex interplay of agent behavior and social structure. The article identifies the peculiarities and the explanatory achievements of this approach and t...

The use of computer simulations in crowd research is a powerful tool to describe and analyse complex social systems. This paper presents CROSS, a generic framework to model crowd simulations as a social scientific tool for understanding crowd behaviour. In CROSS, individuals are represented by social-cognitive agents that are affected by their soci...

We present DIAL, a model of group dynamics and opinion dynamics. It features dialogues, in which agents gamble about reputation points. Intra-group radicalisation of opinions appears to be an emergent phenomenon. We position this model within the theoretical literature on opinion dynamics and social influence. Moreover, we investigate the effect of...

Online shoppers may differ in what they desire from websites based on their experience with a specific website and with online shopping in general. This study investigates the moderating influence of online and website-specific shopping experience on the importance of website criteria. The results from survey data from customers of two bookstores r...

Markets can show different types of dynamics, ranging from stable markets dominated by one or a few products, to fluctuating markets where products are frequently being replaced by new versions. This paper explores the dynamics of markets from a psychological perspective using a multi-agent simulation model. The behavioural rules of the artificial...

This paper explores the dynamics of attitude change in two dimensions resulting from social interaction. We add a rejection mechanism into the 2D bounded confidence (BC) model proposed by Deffuant et al. (2001). Individuals are characterized by two-dimensional continuous attitudes, each associated with an uncertainty u, supposed constant in this fi...

This study investigates the critical role that opinion leaders (or influentials) play in the adoption process of new products. Recent existing reseach evidence indicates a limited effect of opinion leaders on diffusion processes, yet these studies take into account merely the network position of opinion leaders without addressing their influential...

An introduction to the special issue of the journal is presented in which the editor discusses an article on market inequalities in motion picture industry caused by social influences, an article on the role of universities in quantity and speed of innovation in innovation networks in knowledge-intensive industries, and the part of opinion leaders...

We have formalized and parameterized a model for the production of six transport fuels and six fuels blends from six feedstocks through 13 different production chains, and their adoption of by 11 distinct subpopulations of motorists. The motorists are represented by agents that use heuristics to choose a fuel on the basis of three attributes and a...

This paper describes how a work group and a newcomer mutually adapt. We study two types of simulated groups that need an extra worker, one group because a former employee had left the group and one group because of its workload. For both groups, we test three conditions, newcomers being specialists, newcomers being generalists, and a control condit...

Innovation diffusion theory suggests that consumers differ concerning the number of contacts they have and the degree and the direction to which social influences determine their choice to adopt. To test the impacts of these factors on innovation diffusion, in particular the occurrence of hits and flops, a new agent-based model for innovation diffu...

To understand the consequences of the E.U. ban on incandescent lamps, an agent-based model is developed in which consumers are simulated in their lamps purchase behaviour. Consumers are modelled based on heterogeneous preferences and develop opinions on lamps (memory and perceptions), and share these in a social network structure. Lighting technolo...

Cognitive representations are being shaped and determined by interaction with the environment. The social environment constitutes an important part of this environment. Yet in formal models of cognition, there is little attention for processes resulting from social interaction. On the other hand, in formal models of social interaction, little atten...

In the ourishing research area of agent-based social sim- ulation, the focus is on the emergence of social phenomena from the interactions of individual autonomous agents. There is, however, a rela- tive underexposure of the cognitive properties of agents, as the existing agent architectures often focus on behaviour alone. Cognition becomes particu...

We have formalized and parameterized a model for the production of 6 transport fuels and 6 fuels blends from 6 feedstocks through 13 different production chains, and their adoption of by 11 distinct subpopulations of motorists. The motorists are represented by agents that use heuristics to choose a fuel on the basis of three attributes and a social...

This paper is a follow up of the ESSA paper presented by us last year. In this paper we focus on the efficacy of dynamic responses - in particular a price-cut - to a decrease in sales. We observe that dynamic pricing strategies, which respond to market shares, increase the survival rates of products. Moreover we show that a faster response to a dec...

This paper explores the dynamics of attitude change in 2 dimensions (2D) as a result of social interaction. We add a rejection mechanism into the 2D bounded confidence (BC) model proposed by Deffuant et al (2001). Individuals are characterised by twodimensional continuous attitudes, each associated with an uncertainty u, supposed constant in this f...

In this paper we investigate the degree to which two social influences, namely imitation and coordinated consumption, effectuate inequalities in the motion picture industry. We develop an agent-based model based on micro movie visitors' decision-making that generates the observed macro market outcomes. The simulation model makes use of the findings...

This special issue of Advances in Complex Systems presents a collection of selected papers of the 4th Conference of the European Social Simulation Association held in Tolulouse, France on 10–14 September 2007.

Multi-agent simulation is applied to explore how different types of task variety cause workgroups to change their task allocation accordingly. We studied two groups, generalists and specialists. We hypothesised that the performance of the specialists would decrease when task variety increases. The generalists, on the other hand, would perform bett...

In dit artikel onderzoeken we de beïnvloedbaarheid van Nederlandse beleggers. Hiertoe laten we eerst zien dat naast financiële ook intellectuele en sociale behoeften een rol spelen bij beleggen. Daarna maken we onderscheid tussen beleggers die vooral in hun netwerk om informatie zoeken en beleggers die sociale goedkeuring zoeken bij hun beleggingsb...

Dans le modèle de dynamiques d'attitudes (ou opinions) à "confiance limitée" (CL), deux individus se rapprochent lors d'une rencontre si leur différence est inférieure à un seuil. Nous considérons des individus avec deux attitudes, et nous ajoutons au modèle CL un mécanisme de rejet. Si deux individus sont très éloignés sur la première attitude et...

Many marketing efforts focus on promotional activities that support the launch of new products. Promotional strategies may play a crucial role in the early stages of the product life cycle, and determine to a large extent the diffusion of a new product. This paper proposes an agent-based model to simulate the efficacy of different promotional strat...

Marketers employ the four P's — product, price, placement and promotion — in trying to optimize the performance of their products on a market. Both researchers and practitioners in the field of marketing will benefit from increasing their understanding of how the four P's relate to market dynamics and how marketers should employ them in managing dy...

"Diffusions of new products and technologies through social networks can be formalized as spreading of infectious diseases. However, while epidemiological models describe infection in terms of transmissibility and susceptibility, we propose a diffusion model that explicitly includes consumer decision-making affected by social influences and word-of...

Computer simulation allows for the experimental study of dynamic interactions between human behavior and complex environmental systems. Behavioral determinants and processes as identified in social-scientific theory may be formalized in simulated agents to obtain a better understanding of man–environment interactions and of policy measures aimed at...

This paper studies the use of social simulation in linking micro level investor behaviour and macro level stock market dynamics. Empirical data from a survey on individual investors\' decision-making and social interaction was used to formalize the trading and interaction rules of the agents of the artificial stock market SimStockExchange. Multiple...

Many consumer markets display complex behavior, meaning that traditional forecasting models perform at a level that excludes practical use, for instance when predicting the market shares of new products or the effects of marketing strategies. Interaction among consumers, comprising normative influences and word-of-mouth, is one of the key processes...

In processes of attitude change people may employ different mechanisms, for example focussing on arguments (central processing) versus focusing on the reputation of the source (peripheral processing). In this paper we formalise these processes and systematically explore how this affects the relation between two attitude dimensions. Both an aggregat...

This paper describes the consequences of turnover, especially how a work group and a newcomer mutually adapt. We tested two groups, a group in which the task allocation gives space for a newcomer to fit in and a group in which this space was not available. For both groups, we tested conditions with newcomers being specialists, contributing to a spe...

This paper first discusses consumer motives for adopting photovoltaic systems (PV systems) from a behavioural-theoretical perspective. Different motives are discussed within a framework of underlying needs and the time sensitivity of various outcomes. Next, empirical data are presented concerning the motives of buyers of PV systems after a promotio...

In this paper, multi-agent simulation is applied to explore how people organize themselves when they have to perform a task. The multi-agent model that we used is based on the formalization of psychological and organizational theories. Three experiments are presented in which multi-agent simulation is being used to study processes of self-organizat...

This paper investigates micro-macro links in stock markets. Empirical investigations on individual investors' decision-making and interactions are used to formalize agent rules for an artificial stock market. Simulation of the social interactions of multiple agents in this market generates macro results, like stock market prices and returns over ti...

In work groups, task rotation may decrease the negative consequences of boredom and lead to a better task performance. In this paper we use multi agent simulation to study several organisation types in which task rotation may or may not emerge. By looking at the development of expertise and motivation of the different agents and their performance a...

The paper relates virtual dialogues about social simulation, with the implicit reference to Galieo\'s \'dialogues concerning two new sciences\'.

This paper focuses at the dynamics of attitude change in large groups. A multi-agent computer simulation has been developed as a tool to study hypothesis we take to study these dynamics. A major extension in comparison to earlier models is that Social Judgment Theory is being formalized to incorporate processes of assimilation and contrast in persu...

ABSTRACT Amulti-agent simulation for studying opinion dynamics ,in the ,context of two ,opinion dimensions is presented. The agent rules that describe changes in opinion,are based on a theory about persuasion and distinguish between ,central and peripheral processing. Central processing is formalized as assimilating or contrasting the opinion of a...

This paper focuses at the dynamics of attitude change in large groups. A multi-agent computer simulation has been developed as a tool to study these dynamics. A major extension in comparison to earlier models is that Social Judgement Theory is being formalised to incorporate processes of assimilation and contrast in persuasion processes. Results de...

In literature self-organising social behaviour is often described by means of a brain metaphor. These descriptions ei ther discuss some general principles or propose a systems-theoretical analysis, but have not been related to existing psychological theory. In this paper we propose a way of describing self-organising social processes of task alloca...

Striking investor and stock market behaviour have been recurrent items in the worldwide press for the recent past. Crashes and hypes like the Internet bubble are often hard to explain using existing finance frameworks. Therefore, the authors provide a complementing multitheoretical framework that is built on existing finance research to describe an...

This study tries to understand how consumers evaluate channels for their purchasing. Specifically, it develops a conceptual model that addresses consumer value perceptions of using the Internet versus the traditional (physical) channel. Previous research showed that perceptions of price, product quality, service quality and risk strongly influence...

Markets can show different types of dynamics, from quiet markets dominated by one or a few products, to markets with continual penetration of new and reintroduced products. In a previous article we explored the dynamics of markets from a psychological perspective using a multi-agent simulation model. The main results indicated that the behavioral r...

Much ,of our ,daily behaviour ,is habitual. Habits are defined as behaviours that are performed,with a minimum,of cognitive effort. Habits allow for an effective use of our limited cognitive capacities. However, due to this automatising of behaviour, habits are less susceptible for change than reasoned behaviour. Especially when ,a habit provides p...

We report on a series of computer simulation experiments regarding the management of a common resource. We were particularly interested in the effects of uncertainty and satisfaction on the harvesting behaviour of simulated agents. The experimental study of long-term dynamics of threatened resources can hardly be carried out using human subjects. W...